This data product contains derived measurements of ion properties in the solar wind, including
density, temperature, velocity vector. The velocity, temperature, and density of the solar wind proton
population are estimated by fitting each spectrum to a single Maxwellian or a set of Maxwellian ion
populations.
* p1
fit to the “primary” proton peak. This is the peak or largest amplitude observed in a
given l2i spectrum. A locus of measurements is selected that includes the absolute
maximum and at least the 1/e folding, if possible, on either side for this fit.
* a
fit to the “primary” alpha particle (He++) peak, if resolved. For l3i measurements, this is
“guessed” by searching for a secondary peak in each l2i spectrum in the neighborhood
of twice the p1 peak energy.
* 3
if an additional high signal-to-noise feature is present in the l2i spectrum, typically due
to a proton beam or shoulder but also potentially due to a cold minor ion population, a fit
is attempted to the p1-subtracted residuals on this neighborhood. The POP3_MTOQ
variable is used to indicate the species.
* p_tot
if p1 and 3 are successfully fit, and the 3 population is determined to be protons, this
signifies the total proton parameters (np =total proton density, vp = center of mass
velocity, wp = effective thermal velocity, accounting for both populations and their relative
drift).
Version:2.4.1
This data product contains derived measurements of ion properties in the solar wind, including
density, temperature, velocity vector. The velocity, temperature, and density of the solar wind proton
population are estimated by fitting each spectrum to a single Maxwellian or a set of Maxwellian ion
populations.
* p1
fit to the “primary” proton peak. This is the peak or largest amplitude observed in a
given l2i spectrum. A locus of measurements is selected that includes the absolute
maximum and at least the 1/e folding, if possible, on either side for this fit.
* a
fit to the “primary” alpha particle (He++) peak, if resolved. For l3i measurements, this is
“guessed” by searching for a secondary peak in each l2i spectrum in the neighborhood
of twice the p1 peak energy.
* 3
if an additional high signal-to-noise feature is present in the l2i spectrum, typically due
to a proton beam or shoulder but also potentially due to a cold minor ion population, a fit
is attempted to the p1-subtracted residuals on this neighborhood. The POP3_MTOQ
variable is used to indicate the species.
* p_tot
if p1 and 3 are successfully fit, and the 3 population is determined to be protons, this
signifies the total proton parameters (np =total proton density, vp = center of mass
velocity, wp = effective thermal velocity, accounting for both populations and their relative
drift).
| Role | Person | StartDate | StopDate | Note | |
|---|---|---|---|---|---|
| 1. | PrincipalInvestigator | spase://SMWG/Person/Justin.C.Kasper | |||
| 2. | CoInvestigator | spase://SMWG/Person/Anthony.W.Case |
User Guide for Parker Solar Probe SWEAP-SPC Investigation Data Products
Web Service to this product using the HAPI interface.
Access to Data via CDPP/AMDA Web application.
Number density, fitted to the “primary” proton peak
Estimated uncertainty on the number density, fitted to the “primary” proton peak
Thermal velocity = sqrt(2kT/m), fitted to the “primary” proton peak
Estimated uncertainty on the thermal velocity, fitted to the “primary” proton peak
Velocity vector, estimated from the radial thermal velocity fit p1 and flow angle
Velocity vector component upper uncertainties
Velociy vector magnitude
Number density, fitted to the “primary” alpha particle (He++) peak, if resolved
Estimated uncertainty on the number density, fitted to the “primary” alpha particle (He++) peak, if resolved
Thermal velocity = sqrt(2kT/m), fitted to the “primary” alpha particle (He++) peak, if resolved
Estimated uncertainty on the thermal velocity, fitted to the “primary” alpha particle (He++) peak, if resolved
Velocity vector, estimated from the radial thermal velocity fit and flow angle
Velocity vector component uncertainties
Velociy vector magnitude
Number density, fitted to the p1 substracted residuals
Estimated uncertainty on the number density, fitted to the p1 substracted residuals
Thermal velocity = sqrt(2kT/m), fitted to the p1 substracted residuals
Estimated uncertainty on the thermal velocity, fitted to the p1 substracted residuals
Velocity vector, estimated from the radial thermal velocity fit and flow angle
Velocity vector component uncertainties
Velociy vector magnitude
If p1 and 3 are successfully fitted, total proton density
Estimated uncertainty on the number density
If p1 and 3 are successfully fitted, effective thermal velocity
Estimated uncertainty on the thermal velocity
If p1 and 3 are successfully fitted, center of mass velocity vector
Velocity vector component uncertainties
Velociy vector magnitude